This invention relates to a charging control microcomputer device for a vehicle, which externally provides a predetermined value for a voltage regulator adapted to control the output voltage of a charging generator installed in a vehicle or the like and driven by the internal combustion engine thereof, and which is capable of troubleshooting the system according to data received from the charging system.
In general, in a conventional device of this type, the output voltage of a generator driven by a vehicle engine is controlled to a predetermined value which is preset by the voltage regulator installed together with the generator. The output voltage thus controlled charges the battery of the vehicle. In this connection, the voltage regulator may include a temperature compensating circuit, as the case may be, so as to prevent a difficulty wherein the battery charging characteristic changes with temperature. However, since the battery and the voltage regulator are different from each other in installation location and in thermal capacity, in many cases the temperature increase correlation cannot hold and therefore it is difficult to control the output voltage of the voltage regulator to the predetermined value which is most suitable for charging the battery.
The generator is driven by an internal combustion engine as described above. Therefore, the conventional device is disadvantageous, in that, when the aforementioned predetermined value is controlled during the acceleration or deceleration of the engine or according to the speed of rotation thereof to control the mechanical load of the engine, i.e., the generator drive output, it is difficult to externally control the output. Also, it is impossible to detect problems in the charging system made up of the generator, a full-wave rectifier, a voltage regulator, the battery, the wiring, etc, such as those where no current is generated and no control is effected when the exciting circuit is broken, and where the output terminal of the rectifier is disconnected; and the service life of the battery cannot be detected.